Here are some of my latest thoughts… 
Java CheatSheet
Modern Java is a strongly-typed, eagery evaluated, case sensative, yet whitespace insensative language. It uses hierarchies of classes/types to structure data, but also has first-class support for functional-style algebraic datatypes.
Java programs are made up of ‘classes’, classes contain methods, and methods contain commands. To just try out a snippet of code, we can
Open a terminal and enter
jshell; then enter:1 + 2 // The jshell lets you try things out! // Say hello in a fancy way import javax.swing.*; JOptionPane.showMessageDialog(new JFrame(), "Hello, World!");
- Alternatively, in IntelliJ, click Tools then Groovy Console to try things out!
- Finally, VSCode allows arbitrary Java code to be sent to a
jshellin the background(!) and it echoes the result in a friendly way.
💐 Repl Driven Development: /Editor Integrated REPLs for all languages/ 🔁
The 
That is, with Repl aided development, you make software by starting with an already working program (i.e., the repl) then incrementlly “teach it” to be the program you want, by defining & redefining things. Until satisfied, loop: Type/modify code in your editor, press some keys to evaluate what you wrote/modified in the currently running system, and explore/test the resulting runtime.
RDD is programming emphasising fast & rich feedback from a running system. RDD is fantastic for quickly teaching/exploring an idea; as such, the running example of this article will be on servers —no prior experience with servers is assumed. The main examples will be in JavaScript, Python, and Java. (Since JavaScript is just Lisp in C clothing, we will not discuss Lisp.) Since Java is verbose, the power of REPLs really pays off when exploring a new idea. We see how many imports and setup-code simply disappear in the RDD approach, letting you focus on the core idea you're exploring/teaching. For comparison, a traditional self-contained Java server program is ~30 lines long whereas the focused RDD approach is ~4 lines long.
tdlr: This library provides the Emacs built-in C-x C-e behaviour for arbitrary languages, provided they have a primitive cli REPL.
Arabic CheatSheet
My Family Tree
Who's who in the old family tree
A Brisk Introduction to Karate
What are the basic forms of Karate? What is Karate?
“The ultimate aim of karate lies not in victory or defeat but in the perfection of the character of its participants … to subdue the enemy without fighting is the highest skill, know your enemy and know yourself, in a hundred battles you will not be defeated” says Gichin Funakoshi —known as The Father of Modern Karate.
Karate means “empty hand” and was developed on the island of Okinawa —part of modern-day Japan. The major styles (“Ryu”) are Shotokan, Wado-ryu, Shito-ryu, and Goju-ryu —many other styles of Karate are derived from these four. I'm focusing on Goju-Ryu in this article: Goju-Ryu was founded by Chojun Miyagi; whose colleague, Gichin Funakosi, founded Shotokan-Ryu.
Occasionally one sees Karate-Do, which means “the way of the empty hand”. This usage is a reminder that Karate is not just about fighting, but is also a spiritual discipline.
The basic form of Goju-Ryu karate is Sanchin, “3 battles”: The battles of the mind, the body, and the spirit. However, this was considered a bit difficult for beginners, and so new forms were needed as a way of introducing fundamental karate forms to a wider audience. There are the “peaceful and safe” forms known as Pinan/Heian, the “first course” or Taikyoku forms, the “popularising forms” known as Fukyugata —the second of which was rebranded as “attack & smash”, Gekaisai— and, finally, there is the so-called Dachi-waza form. This last one is relatively new, and aims to be a smooth introduction to the world of forms/Kata.
In this article, I'd like to discuss the basic forms and their relationships.
